The present invention relates generally to launderable rubber backed floor mats of the type which have a pile surface on one side and a rubber or rubber-like material on the other side and a continuous process for producing the same. More particularly, the invention relates to the continuous production of floor mats involving the extrusion of a vulcanized thermoplastic elastomer as a backing material for a tufted fabric composite.
Dust control mats and other floor coverings having a pile side and a rubber backing are generally used in access ways where people tend to brush or scrape their feet in order to prevent carrying moisture and/or dirt into other areas of the premises. Normally these mats are located in areas of high pedestrian traffic such as doorways.
The art includes a number of configurations and features for various floor mats. Some patents which are believed to be illustrative of known floor coverings include U.S. Pat. No. 3,306,808 to Thompson, et al. issued Feb. 28, 1967; U.S. Pat. No. 4,741,065 to Parkins issued May 3, 1988; U.S. Pat. No. 4,886,692 to Kerr et al. issued Dec. 12, 1989; U.S. Pat. No. 5,227,214 to Kerr et al. issued Jul. 13, 1993; U.S. Pat. No. 5,240,530 to Fink issued Aug. 31, 1993; and U.S. Pat. No. 5,305,565 to Nagahama et al. issued Apr. 26, 1994; the teaching of all of which are incorporated herein by reference.
As will be appreciated by those of skill in the art, floor mats have conventionally consisted of a plurality of tufts in a primary backing adhered to a vulcanized thermoset rubber backing. Such a backing gives dimensional stability to the fabric surface while maintaining the mat""s integrity during industrial wash processing. Heretofore, the production of launderable floor mats has relied on the use of thermoset rubber backings based on nitrile polymer formulas. While such mats perform very adequately, the manufacturer of such mats has historically been presented with certain limitations due to the formation of the mats as modular units as opposed to the continuous production made possible by the present invention.
Mats formed using thermoset rubber backings require the stationary compression and application of sufficient heat and pressure to vulcanize the rubber backing and adhere it to the fabric. Such batch operations are limited by the curing rate characteristics of the thermoset rubber. Additionally, the process has historically involved cutting the thermoset rubber to length, positioning the rubber backing on a carrier belt or conveyor and thereafter laying the tufted fabric onto the rubber backing and fusing the components together. Once vulcanized, any excess rubber not necessary for the finished specified dimensions of a thermoset mat is cut away and discarded rather than being easily recycled as in the present invention. The use of a process which can deposit an appropriate backing material onto a fabric substrate in a continuous manner thereby producing a mat material which can be cut to given dimensions therefore represents a useful advancement over the art.
In light of the foregoing, it is a general object of the present invention to provide a mat formed by the continuous disposition of a vulcanized thermoplastic elastomer onto a tufted fabric substrate.
It is a related object of the present invention to provide a process for depositing vulcanized thermoplastic elastomer onto a fabric substrate to achieve a desirable mat configuration.
Accordingly, it is a feature of the present invention to provide a continuous mat forming process wherein layers of adhesive and backing materials are deposited in a continuous fashion as layers across a tufted fabric composite.
In one aspect of the present invention a novel dust control mat is provided comprising a plurality of tufts in a primary base. A layer of thermoplastic adhesive is used to adjoin the primary base to a vulcanized thermoplastic elastomer backing which has been deposited continuously across the adhesive backed fabric. The thickness of the vulcanized thermoplastic elastomer layer is between about 20 mils and about 40 mils and preferably in the range of about 30 mils. In the preferred practice of the present invention, a stabilizing layer of woven or nonwoven thermoplastic scrim or film will be deposited on the underside of the thermoplastic elastomer backing and a second layer of vulcanized thermoplastic elastomer will be deposited across the scrim in a sealing manner. The thickness of this second layer of vulcanized thermoplastic elastomer will be in the range of about 20 and 40 mils and preferably about 30 mils.